Miner s lamp



Nov. 12, 1935, G, WHEAT 2,021,111

I MINER s LAMP Filed Decf28, 1932 2 Sheets-Sheet 1 ee 3O 2? o 31 5 mv m'oza.

I BY

'ATTO Y:

Patented Nov. 12, 1935 "UNITED STATES MINERS LAMP Grant Wheat, Marlboro, Mass, assignor to Koch.-

ler Manufacturing'Compa-ny, Marlboro, Mass, a corporation 01* Massachusetts Application December 28, 1932, Serial No. 649,146

-6 Claims. (Cl. 240-113) This invention .relates'to miners'lamps and other portable lamps of essentially the same general character.

It aims to improve lamp apparatus of this type with a view to simplifying its construction and .reducing the expense of manufacture, while at the same time protecting it from accidental short circuiting and from mischievous tampering .by the miners themselves.

said rack;

Fig. 2 is a horizontal, sectional View through a portion of the rack shown in Fig. 1;

Fig. 3 is a perspective view showing details of the connector which is included in the circuit connections between the battery and'the headpiece of the lamp; and

Fig. 4 is a rear elevation of the headpiece-and the connector, the casing enclosing the connector being shown in-section.

Referring first to Fig. l, the miners lamp there shown comprises a storage battery, indicated in general at 2, a headpiece 3, and a cord or cable 4 including conductors which supply current from the battery to the electric lamp 5 in the headpiece 3. The headpiece is shown morein detail in Figs. 3 and 4. It is designed to be worn on the miners cap and for this purpose is provided with a spring clamp 6 for attachment to a plate with which the cap is equipped. In general organization this lamp resembles that shown and described in my earlier patents, such, for example; as my Patent No. 1,757,887, granted May 6, 1930. The headpiece, in addition to carrying a main electric lamp 5, also is equipped with a smaller emergency lamp 1, Fig. 1, which gives light enough to enable the miner to see his way out of the mine in the event that the main lamp burns out, and the headpiece is equipped with a switch arranged to be operated by the knob 8, Figs. 3 and 4, so that the miner can turn either lamp bulb 5 or i on or off, as he desires.

Since the battery 2 is of the secondary type it must be recharged at intervals. This has been conveniently accomplished heretofore by locating charging terminals in some exposed position on the battery or the headpiece, providing a switch for controlling the connection between these terminals and the battery terminals, and locking the switch so that the miners cannot operate it and thus render the charging ,ter- 5 minals alive. According to the present invention, however, both the switch and its locking means are eliminated from the battery and'the headpiece, and a connector is included in the circuit between the battery and the headpiece,.this 10 connector comprising parts which may be .separated to disconnect the headpiece from the battery both electrically and mechanically.

Referring more particularly to. Figs. 3 and4, the connector there shown comprisestwo members Ill-and l2, respectively,-both made of insulating material. One forms a part of the headpiece assembly and is equipped with metal pins 13 insulated from each other, while the other forms the terminal-for the cord and is provided with metal sockets or thimbles 14 to receivethe pins I3. In the particulararrangement shown the pins are mounted on the part 12 and are connected to the conductors which lead through, the switch above described to the electric lamps ,5

and I, the part 12 being rigidly secured to and forming the end of the shank or neck of the headpiece 3. Thetwo metal socket members are connected, respectively, to the two conductors in the cord 4, and the insulating .member' 10 is rigidly secured to the endof this cord.

When, the two, parts of the connector are brought operated by the miner so that the contacts and those parts which carry current will. not only beprotected against accidental short circuiting, with the consequent danger of producing a spark whichmight cause anexplosion if inflammable gas were present, .but, in addition, to prevent .the miners from tamperingwith the conductors and thus creating a shortcircuit either acci- .dentally. or intentionally. For this purposetwo hook-shaped latches ,15 .|-5 are pivoted on the .50

headpiece at opposite sides of the connector member I2 and are arranged to engage shoulders in opposite sides of the connector-member Ill formed by notching-this memberv as shown at. 16.

.Access to these latches or looking members nor- ,5;

mally is prevented by the fact that they are enclosed in a sheet metal casing it. Each latch has a spring il associated with it and bearing against the casing to hold the hook of the latch in its respective notch it.

It will be seen from an inspection of Fig. 4 that one end of thecasing l8 is provided with a bottom through which an aperture is formed of such asize as to receive the reduced portion of the connector member I, the portion of the casing immediately around this aperture bearing against a shoulder 26, Fig. 3, formed on said member. Consequently, when the parts of the connector are pushed together to close the connector, the hooks of the latches I5!5 snap into the notches l6-l6 and lock the parts in their closed relationship, as shown in Fig. 4. This operation also locks the casing in its operative position since the latches must first be released before the parts of the connector can be separated to release the casing. The casing thus prevents access either to the locking means or to the parts of the connector in which the contacts are located.

The locking mechanism may be operated to releasethe latches by bringing a horse-shoe magnet or an electro-magnet into such a position that its poles lie at opposite sides of the casing l8 and outside the two hooks. The casing should be made of some non-magnetic material such as brass, aluminum, or the like, while the latches are ,made of some magnetic material, such as includes a lower shelf 22 for supporting the batteries and an upper shelf 23 on which the headpieces may be placed. Preferably a guide 24 is associated with the lower shelf and is provided "with a series of notches 25, each ofsuitable width to receivecan individual battery. Associated with the upper shelf 23 is an upright panel 26 carrying a series of pairs of pins 27, each pair corresponding in dimensions to the pins [3, Fig. 3, of the connector.

strips 28 secured to the back of the panel. Consequently, by plugging the socket member It on to any pair of pins 21 the battery will be connected into the charging circuit.

If a constant current series charging system is used, it is necessary to provide some means for closing the circuit between those pins 21 which are not in use. This is conveniently accomplished in the construction shown by associating two spring contacts 36 with each pair of pins and connecting the lower ends of the contacts ad-. ,jacent to the points at which they are afiixed to the panel 26 by a coil M of wire having a resistance corresponding substantially to that of a battery. Preferably the upper ends of these spring members are bevelled, as best shown in Fig. 2, so that when the socket member 10 is pushed on to the pins it will force the contacts apart and thus interrupt any flow of current through the resistance coil 3|. When the socket member I6 is withdrawn the contacts 30 will spring back into contact with the pins 21 and thus will auto- These pins are connected in series in a charging circuit by means of metal r matically close the circuit again through these 7 pins, thus short circuiting them. I It will be noted that one of each pair of pins 21 is larger in diameter than the other and that the sockets in the connector l0 differ correspondingly'in diameter so that there is no, possibility of reversing the polarity of the battery during the charging operation. Because of this arrangement the pins [3 differ likewise in size. V

The invention thus provides a miners lamp structure which is simplified substantially as compared with the more common lamps of this character now on the market, while at the same time being amply protected against short circuiting either accidentally or intentionally. In addition, the nature of this construction is such that it permits the use of an extremely simple form of charging rack. It also facilitates the interchange and substitution of one headpiece for another'in the;

event that an individual headpiece requires repairs. A similar interchange of batteries for an individual headpiece can be made if trouble should develop in the battery.

While I have herein shown and described a preferred embodiment of my invention, it will be evident that the invention may be embodied in other forms without departing from the spirit or scope thereof. For example, some other form of lock could be substituted for the magnetically releasable lock usedwith the connector, the essential'point lamp, of a connector having contacts in circuit with said conductors, said connector having parts readily separable from each other to open the circuit and to disconnect said headpiece both' mechanically and electrically from said battery, a lock for holding said connector closed, and a casing preventing access to said lock said casing also being held closed by said lock.

2. In a miners lamp, the combination with a headpiece, an electric lamp mounted in said headpiece, a storage battery, and a cord for connecting said battery with saidheadpiece and including conductors for supplying current to said lamp, of a connector having contacts in circuit with said conductors, said connector having parts readily separable from each other to open the circuit and to disconnect said headpiece from said battery, and a normally inaccessible lock for holding said connector closed, said lock being arranged to be released by the presentation thereto of a magnet in a predetermined relationship .to the lock.

3. In a miners lamp, the combination with a headpiece, an electric lamp mounted in said said parts of said connector against separation, and a-casing preventing access to said latch, said casing and latch being so arranged that the latch may be released by holding a magnet in a predetermined relationship to the casing.

4. In a miners lamp, the combination of a headpiece, an electric lamp mounted in said headpiece, a cord for connecting a storage battery with said headpiece and including conductors for leading current to and from the headpiece, a connector having contacts in circuit with said conductors and including two members, one of which forms a part of the headpiece assembly and the other forming a terminal for said cord, said members being readily separable from each other to open the circuit and to disconnect said headpiece both electrically and mechanically from said cord and battery, means for locking said connector in its closed condition, including means for preventing the separation of said members except through the use of a special tool, and means for preventing access to said locking means and to said contacts.

5. In a miners lamp, the combination of a headpiece, an electric lamp mounted in said headpiece, a cord for connecting a storage battery with said headpiece and including conductors for leading current to and from the headpiece, a connector having contacts in circuit with said conductors and including two members, one

of which forms a part of the headpiece assembly and the other forming a terminal for said cord, said members being readily separable from each other to open the circuit and to disconnect said headpiece both electrically and mechanically from said cord and battery, a casing enclosing said contacts and preventing access to them, and normally inaccessible means for locking said casing in its operative position.

6. In a miners lamp, the combination of a headpiece, an electric lamp mounted in said headpiece, a cord for connectinga storage battery with said headpiece and including conductors for leading current to and from the headpiece, a connector having contacts in circuit with said conductors and including two members, one of which forms a part of the headpiece assembly and the other forming a terminal for said cord, said members being readily separable from each other to open the circuit and to disconnect said headpiece both electrically and mechanically from said cord and battery, and a normally inaccessible lock for holding said connector closed, said lock being arranged to be released by the presentation thereto of a magnet in a predetermined relationship to said lock.

GRANT WHEAT. 

